PCWorldreports on five ways in which your online privacy could be invaded:

These days, you need a healthy dose of naiveté to think that your personal data isn’t routinely bought, sold or tracked online. Tracking cookies are the norm on popular websites, and tech giants such as Google and Facebook have a reputation for mishandling and/or overcollecting users’ personal data.

But while those issues receive lots of attention, corporations and governments may keep an eye on you in other, lesser-known ways. Here are five online privacy intrusions that you might not know about.

The Government Might Be Building a File on You

The idea that government agents are reading your email messages and listening to your phone calls sounds like the stuff of conspiracy theorists, but saner minds claim that it’s possible. According to several former National Security Agency employees-turned-whistleblowers, the government is building a dossier on practically every U.S. citizen, drawing on information from e-mails and phone calls. And as Wired has reported, the NSA is building a massive spy center to sift through all the data and figure out who’s a threat. […]

What You Can Do: Of course, you can’t opt out of this type of data collection, but you can hope that Congress doesn’t renew the FISA Amendments Act, which would renew a Bush administration law that allows the government to collect large amounts of information from the “international communications” of American citizens. The Electronic Freedom Foundation is imploring citizens to write their members of Congress about the issue.

Ebooks Know What Kind of Reader You Are

In the digital age, your reading habits are an open book to companies like Amazon, Barnes & Noble, and Apple. As TheWall Street Journal reports, ebook sellers can easily track reading data—data such as how long you spend reading, how far you get in a book, what text you search for, and what you read next. Not all companies are open about what they collect, but Barnes & Noble’s vice president of ebooks, Jim Hilt, confirmed to the Journal that the bookseller is “in the earliest stages of deep analytics,” and uses the data to determine which books to sell on its Nook ebook reader products.

There’s no evidence that booksellers use reading data for nefarious purposes, such as sharing your habits with marketers or government agencies. The bigger concern, for the moment, is that authors and publishers may tailor the content they create or publish to sync with the reading tastes of the mainstream, which would discourage creative risk-taking and diminish the variety of available content.